1. Field of the Invention
The present invention relates to a substrate treatment system, a substrate transfer system, and substrate transfer method for use in transferring a substrate such as a semiconductor wafer and an LCD substrate from a cassette station to a process station.
2. Discussion of the Background
Recently, sizes of semiconductor wafers have been increased. With the size increase, the wafers tend to be processed one by one in semiconductor device manufacturing processes. For example, in a complex process system (resist coating and developing are performed in one process), substrates are taken out from a cassette one by one, processed in a process unit, and returned to the cassette one by one.
In a conventionally-used coating and developing process system as shown in FIG. 1, a plurality of cassettes CR are placed on a cassette station 102. Wafers W are taken out from the cassette CR one by one by means of a wafer transfer mechanism 105, loaded into a process station 101, and subjected to a resist coating and developing process. The wafer transfer mechanism 105 comprises a movement unit 103 and an arm 104. The arm 104 is moved separately by means of the movement unit 103 in the X, Y, and Z axis directions and rotated about the Z axis by a xcex8 angle. The processed wafer W is returned to the cassette CR on the cassette station 102 by the wafer transfer mechanism 105.
To prevent particles from attaching onto the wafer W, the resist coating and developing process system is positioned in a clean room where clean air constantly flows downwardly.
Furthermore, to prevent particles from entering the cassette CR during the conveyance of the cassette, a detachable cover is provided to the opening of the cassette CR. However, when the cassette CR is placed in the cassette station 102 with the cover removed, the cover intervenes in the down-flow of clean air in the process system, creating an air flow which will allow invasion of particles into a process station 101.
In the wafer processing step, a washing device (scrubber) is used for washing the front and rear surfaces of the wafer with a brush. The washing device comprises a cassette station 401 and a process station 402. The process station 402 comprises a center transfer passage 420, a front-surface washing unit 421, a rear-surface washing unit 423, wafer reverse units 427, 428, heating and cooling units 425, 426, and a wafer transfer mechanism 403.
To prevent particles from attaching to the wafer as much as possible in such a washing device, the wafer cassette CR is placed in an airtight chamber (So-called SMIF POD) 413 and the SMIF POD containing the cassette CR is transferred to the cassette station 401. In the cassette station 401, the SMIF POD 413 is descended to the wafer transfer portion while the SMIF POD 413 is kept airtight. In the SMIF system, wafers are transferred one by one from the cassette CR of the wafer transfer portion to the process station 402, washed, and returned to the cassette CR. Thereafter, the wafer cassette CR is ascended and returned to the SMIF POD 413 on the cassette station 401.
However, the conventionally-used device has a problem. If a wafer W protrudes from the cassette CR, the protruding wafer sometimes hits against the upper wall of the wafer transfer portion and causes damages when the wafer cassette CR is returned to the SMIF POD 413. Furthermore, when the wafer protrudes from the cassette CR, the protruding wafer interferes with a mapping sensor 21b, inducing misoperation of mapping, as shown in FIG. 9.
An object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method capable of loading and unloading a substrate to a cassette with a cover without disturbing a down-flow of clean air in the cassette station, capable of preventing particles from attaching to the substrate, efficiently, and capable of preventing particles from flowing into the process station side from the cassette station side.
Another object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method producing no substrate breakage when a cassette is returned to a cassette mounting portion from a substrate transfer portion.
(1) A substrate treatment system according to the present invention comprises
a cassette table for mounting a cassette which has an opening portion for loading and unloading a substrate and a cover detachably provided to the opening portion,
a process portion for processing the substrate stored in the cassette on the cassette table,
a transfer arm mechanism for taking out the substrate from the cassette on the cassette table, transferring the substrate to the process portion and returning a processed substrate to the cassette on the cassette table,
a partition member provided between the transfer arm mechanism and the cassette table, for separating an atmosphere on the transfer arm mechanism side from that on the cassette table side,
a passage for passing the substrate taken out from the cassette on the cassette table by the transfer arm mechanism and for passing the substrate to be returned to the cassette on the cassette table, the passage being formed in the partition member so as to face the opening of the cassette on the cassette table,
a cassette moving mechanism for moving the cassette placed on the cassette table so as to be closer to the passage or to be farther from the passage, and
a cover removing mechanism for attaching or detaching of the cover to the opening portion of the cassette.
According to the present invention, a down flow of clean air will not be disturbed by open/shut movement of the cassette cover, in the transfer room.
(2) A system according to the present invention comprises
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
substrate transfer means for loading/unloading a substrate from the cassette through the opening portion,
a partition member for separating a space on a cassette-side from a space on a substrate-transfer-means side, the partition member having a transfer window for transferring the substrate between the spaces, and
a cover transfer mechanism for removing the cover from the cassette and transferring the cover to the lower space on the substrate-transfer-means side through the transfer window.
According to the present invention, the down flow of clean air will not be disturbed by the cover itself in the transfer room when the cover is attached to or detached from the cassette.
(3) A substrate treatment system according to the present invention comprises:
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
a cassette table on which a cassette is to be mounted,
substrate transfer means for loading/unloading a substrate through the opening portion of the cassette mounted on the cassette table,
a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces,
a cover storage portion formed on a side of the cassette table, facing the space on the substrate-transfer-means side, for storing a cover removed from the cassette, and
a cover transfer mechanism for removing the cover from the cassette through the transfer window, transferring the removed cover to the space on the substrate-transfer-means side, and storing the cover in the cover storage portion.
According to the present invention, the down flow of clean air will not be disturbed in the transfer room when the cassette is opened and shut. In addition, particles are prevented from attaching to a substrate in the transfer room and the process chamber 31A.
(4) A substrate transfer system according to the present invention comprises,
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
substrate transfer means for loading/unloading a substrate from the cassette, the substrate transfer means being provided in a transfer room whose pressure is set higher than the inner pressure of the cassette,
a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces, and
a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to a lower space of the substrate transfer means.
According to the present invention, since the inner pressure of the transfer room for transferring the substrate is set higher than the outside pressure, particles can be prevented from entering the transfer room from the outside.
(5) A substrate treatment system according to the present invention is provided in a clean room. The substrate treatment system comprises:
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
substrate transfer means for loading/unloading a substrate from the cassette, the substrate transfer means being provided in a transfer room whose pressure is set higher than the inner pressure of the clean room,
a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces, and
a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to a lower space of the substrate-transfer-means side.
According to the present invention, since the pressure of the transfer room is set higher than an inner pressure of the clean room, particles can be prevented from entering the transfer room from the clean room.
(6) A substrate treatment system according to the present invention comprises:
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
a transfer room separated by a partition member having a first transfer window, for transferring a substrate from the cassette,
substrate transfer means provided in the transfer room, for transferring a substrate from the cassette, and vice versa, through the first transfer window,
a cover removing mechanism provided in the transfer room for removing a cover from the cassette through the first transfer window and transferring the cover to a lower space on a substrate-transfer-means side,
a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to the lower space of a substrate-transfer-means side, and
a process chamber 31A for processing the substrate transferred from a second transfer window. The process chamber 31A being provided adjacent to the transfer room, which has a second transfer window for transferring a substrate by the substrate transfer means between the process chamber 31A and the transfer room.
(7) A substrate treatment system according to the present invention comprises:
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
a transfer room set at a higher pressure than an inner pressure of the cassette and having a first transfer window for transferring a substrate from the cassette,
substrate transfer means provided in the transfer room, for transferring a substrate from the cassette, and vice versa, through the first transfer window,
a cover transfer mechanism provided in the transfer room, for removing a cover from the cassette through the first transfer window and transferring the cover to a lower portion of a space of the substrate transfer means side,
a process chamber 31A for processing the substrate transferred through a second transfer window, the process chamber 31A being set at a higher pressure than an inner pressure of the transfer room, being disposed adjacent to the transfer room, and having the second transfer window for transferring a substrate by the substrate transfer means to the transfer room.
According to the present invention, since the pressure of the process chamber 31A is set higher than the inner pressure of the transfer room, particles can be prevented from entering the process chamber 31A from the transfer room.
(8) A substrate transfer system according to the present invention comprises a process portion for processing a substrate and a transfer portion for transferring the substrate to the process portion, and vice versa. In this substrate transfer system, the transfer portion comprises
a mounting portion for mounting a cassette in which a plurality of substrates are horizontally placed,
a substrate transfer portion provided below the mounting portion, for transferring the substrate to the process portion,
moving means for moving the cassette between the mounting portion and the substrate transfer portion,
detection means for detecting a protruding substrate when the cassette moves to the mounting portion from the transfer portion, and
pushing means for pushing a protruding substrate detected by the detection means into the cassette.
(9) A substrate treatment system comprises a process portion for processing a substrate under airtight conditions and a transfer portion for transferring a substrate to the process portion under the airtight conditions. In this substrate treatment system,
the transfer portion comprises
a mounting portion for mounting an airtight container containing a cassette in which a plurality of substrates are horizontally placed,
a substrate transfer portion provided in an airtight space communicated with the process portion below the mounting portion,
moving means for moving the cassette between the table and the substrate transfer portion,
detection means for detecting a protruding substrate when the cassette moves from the substrate transfer portion to the mounting portion, and
pushing means for pushing the protruding substrate into the cassette when the protruding substrate is detected by the detection means.
(10) A substrate transfer system for transferring a substrate comprises:
a mounting portion for mounting a cassette in which a plurality of substrates are placed horizontally,
a substrate transfer portion provided below the mounting portion, for transferring a substrate to other system, and vice versa,
moving means for moving the cassette between the mounting portion and the substrate transfer portion,
detection means for detecting a protruding substrate when the cassette is moved from the substrate transfer portion to the mounting portion, and
pushing means for pushing a protruding substrate detected by the detection means.
(11) A method for transferring a substrate comprises the steps of:
(a) mounting a cassette in which a plurality of substrates are placed horizontally, on a mounting portion,
(b) moving the cassette to a substrate transfer portion below the mounting portion,
(c) transferring the substrate in the cassette to other system at a substrate transfer portion,
(d) receiving the substrate from the other system into the cassette positioned at the substrate transfer portion,
(e) moving the cassette containing the received substrate to the mounting portion,
(f) detecting a protruding substrate when the cassette is moved to the mounting portion, and
(g) pushing the protruding substrate detected into the cassette.
(12) A method for transferring substrate under airtight conditions, comprises the steps of:
(A) mounting an airtight container on a mounting portion, the airtight container containing a cassette in which a plurality of substrates are horizontally placed,
(B) moving the cassette to a substrate transferring portion positioned in an airtight space below the mounting portion,
(C) transferring the substrate in the cassette to other system at the substrate transfer portion, the other system being provided in an airtight space communicated with the airtight space,
(D) receiving a substrate into the cassette positioned at the substrate transfer portion from the other system,
(E) moving a cassette containing the received substrate to the mounting portion,
(F) detecting a protruding substrate when the cassette is moved to the mounting portion, and
(G) pushing the protruding substrate detected into the cassette.
Additional object and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.